Iphone 5 & 5s no charge

I have many many phones iphone 5 & 5s have problem with charge i can’t charge it if the battery 0 or 1% i have open the phone and remove the battery and make it in the power supply and charge it to 4 or 5 % when i back the battery the charge normal

I chage flex charge and battey and ic charge U2 and the problem not solved
Please any help